Transcript What is Life? - Walla Walla Community College

What is Nature?
A course based on the study of LIFE:
Nsci&150 is a study of life’s
diversity…which is Nature!
• Nature can be identified as:
• The world of living entities
combined with and living because
of the environment.
So, what is Life?
• Biology is the Science that studies
life..
• What is Biology defined as?….
• What Is Science? What does this
word Science mean to you?
How do you know…
• that what you, hear, read, see,
feel, taste, touch is real VS.
fiction / fantasy?..
• What is Diversity, and what
does this word mean to you?
“Real Science”… is Objective!
• First, what does the term Objective
mean…i.e. what is it Defined as?…
• “Of having to do with a Material,
reality based physical Object, as
distinguished from a mental image or
illusion..”
More Science terms...
• What does the term Subjective mean? What
is it defined as….
• “An Occurrence, or subject matter that takes
place or has existence in a person’s mind.
Something that is based on mental image or
thoughts., but not in reality. Of an illusion in
design and existence.”
Which of the following words then
pertains to true science?
• Objective
• or
• Subjective?
Now, by you knowing the definitions of
Objective and Subjective...
True Science would be identified as:
• _________ and not _________.
• -True Science is based on fact and NOT
illusion or thought based faith.
• -“The external world, not internal conviction,
must be the testing ground for scientific
beliefs.”
What is this...... and what are life’s properties?
Life
• How do we know it, life, from a piece of
chalk, interactive software, video game?
What are life’s Properties?
• 1. LIFE has Structured Organization
• 2. LIFE has a Use of / for the
manufacture of Energy.
• 3. Life maintains an internal
constancy: a state of Homeostasis via
feedback
Life properties…continued
• 4. Life Has Reproduction, growth,
and development…meaning
what?
• 5. Life has a Response to Change
via irritability (short term) or
adaptations
1. Life Has Structured
Organization
• From Atoms to Biosphere…the terms
begin.
• Without order and structure there is no life
• BUT...Random events can lead to either
structure or disorder, or BOTH!
2. LIFE Has a Use of / for the
manufacture of energy
• Metabolism the chemical processes of
identified as having life in two “parts”.
• 1. Anabolism: to make, build
• 2. Catabolism: to take apart, destroy
3. LIFE has to Maintain an
internal constancy via
• a. Homeostasis: a system of “balanced”
chemistry allowing for life to be, exist,
perpetuate.
And
• b. Feedback: in which there are two
forms: negative and positive. One
“stops”/lessens an input of info, and the
second perpetuates the info. “reply”
4. Life Has Reproduction, growth,
and development
• So what?
• Define / Expand on the listed three, and tell
me why reproduction via sex is so important
to life.
• What is sex used for?
• Does all reproduction have sex as a
component of it?
5. Life has a Response to internal
and external environmental Change
via irritability or adaptations..
• Life “Irritability” .
• ..short term annoyances, problems,
concerns that cause change in the
entity in its life.
• What is Adaptation?
What is inheritance?
Define it, describe it…
• What is the material of
inheritance?
• DNA stands for…?
• Deoxyribonucleic acid.
• What are genes, describe this
term?
Domains to life are Three:
http://www.phage.org/links_cell_biology.htm
is a link to cell bio web sites, to more on domains click here.
•Archae
•Eubacteria(here)
•Eukaryota (here)
(here)
Archae: The old, extreme
bacteria of Earth
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The old, extreme bacteria of Earth
Collectively called “Extremophiles”.
The Three “Types: Of Archaebacteria are:
1. Methanogens (methane-producers)--are responsible
for swamp gas.
• 2. Extreme Thermophiles--live in hot springs and
black smokers in the ocean.
• 3. Extreme Halophiles--live in saturated brine and salt
crust areas.
Eubacteria / Bacteria:
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Cyanobacteria: are Photosynthetic
And the “Non-photosynthetic bacteria
Bacteria come in four basic shapes:
Coccus, Spirralli, Bacillus, and Spirocheta
The Following images are from:
http://www.phage.org/black04.htm
Cocci
Bacilli
Spirillum
Spirochete.. Borrelia
Cyanobacteria “also “blue
green algae) a misnomer
• These contain pigments that the
entity uses to convert sunlight
energy into carbohydrates
“food”.
• called Photosynthesis
Cyanobacteria
Domain: Eukaryota
• Cells with a nucleus and membrane bound
organelles.
• Eu True Karyo Kernel
• 4 Kingdoms: Identified by:
• Cellular structures, and Energy
acquisition
• Protista, Fungi, Plantae, Animalia
GROUP: Protista
• Single and multicelled (but
without true vascular tissues).
• Heterotrophic and
Autotrophic
• Sexual and asexual
K: Fungi
• Single and multi-celled , Chitin
cell wall
• Heterotrophic
• Sexual and asexual
K: Plantae
• Multi-celled (some with and
without true vascular
tissues). Cellulose cell walls
• Mostly Autotrophic
• Sexual and asexual
K: Animalia
• Multi-celled with and without
true tissues
• Heterotrophic, no cell walls
• Sexual and asexual
Scientific Method
• Or…How to be a true scientist:
• 1. STEP One: Observation. Then ask a
question
• 2. Hypothesis
• Data request, test hypothesis, multiple
inquiries,repeated data analysis, published
• Theory
• Law
Controlled experiments
• Experimental Controls:
• -Positive control
• -Negative control (placebo)
I. Cells-• Identified / defined as the smallest
whole units of Life -• These fundamental units exhibit
all the characteristics of life.
The Cell Theory emerges
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Robert Hooke (coined the term “cell”)
Schleiden “cells are basic unit of plants”
Schwann: compared animal to plant cells
Together they stated all life forms are
composed of cells.
• Virchow “cells come from pre-existing
cells”
Cell facts
• Cell Size --what is this
determined on?
• Cell volume increases faster
than cell surface area.
• This is the Determining factor
to the size of a cell
Prokaryotic Cells
• The Hallmark of a prokaryote
is its lack of a true nucleus.
Eukaryotic Cells
• Plants, animals, fungi, and
Protista all have eukaryotic
cells